US6844471B2 - Method for the conversion of a Z-isomer into E-isomer - Google Patents
Method for the conversion of a Z-isomer into E-isomer Download PDFInfo
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- US6844471B2 US6844471B2 US10/310,048 US31004802A US6844471B2 US 6844471 B2 US6844471 B2 US 6844471B2 US 31004802 A US31004802 A US 31004802A US 6844471 B2 US6844471 B2 US 6844471B2
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- Prior art keywords
- ethene
- general formula
- phenyl
- substituted phenyl
- disubstituted phenyl
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- 238000000034 method Methods 0.000 title claims abstract description 32
- 238000006243 chemical reaction Methods 0.000 title claims abstract description 10
- -1 (Z)-1-(3,5-disubstituted phenyl)-2-(4-substituted phenyl)ethene Chemical class 0.000 claims abstract description 29
- 125000004178 (C1-C4) alkyl group Chemical group 0.000 claims abstract description 22
- LUKBXSAWLPMMSZ-OWOJBTEDSA-N Trans-resveratrol Chemical compound C1=CC(O)=CC=C1\C=C\C1=CC(O)=CC(O)=C1 LUKBXSAWLPMMSZ-OWOJBTEDSA-N 0.000 claims abstract description 12
- 125000003118 aryl group Chemical group 0.000 claims abstract description 5
- 125000003107 substituted aryl group Chemical group 0.000 claims abstract description 5
- YMWUJEATGCHHMB-UHFFFAOYSA-N Dichloromethane Chemical compound ClCCl YMWUJEATGCHHMB-UHFFFAOYSA-N 0.000 claims description 12
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 claims description 9
- HEDRZPFGACZZDS-UHFFFAOYSA-N Chloroform Chemical compound ClC(Cl)Cl HEDRZPFGACZZDS-UHFFFAOYSA-N 0.000 claims description 8
- 239000000203 mixture Substances 0.000 claims description 7
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 6
- 229910052736 halogen Inorganic materials 0.000 claims description 6
- 150000002367 halogens Chemical class 0.000 claims description 6
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 claims description 4
- WYURNTSHIVDZCO-UHFFFAOYSA-N Tetrahydrofuran Chemical compound C1CCOC1 WYURNTSHIVDZCO-UHFFFAOYSA-N 0.000 claims description 4
- 230000003197 catalytic effect Effects 0.000 claims description 4
- 239000003638 chemical reducing agent Substances 0.000 claims description 4
- 150000001875 compounds Chemical class 0.000 claims description 4
- HGCIXCUEYOPUTN-UHFFFAOYSA-N cyclohexene Chemical compound C1CCC=CC1 HGCIXCUEYOPUTN-UHFFFAOYSA-N 0.000 claims description 4
- LPIQUOYDBNQMRZ-UHFFFAOYSA-N cyclopentene Chemical compound C1CC=CC1 LPIQUOYDBNQMRZ-UHFFFAOYSA-N 0.000 claims description 4
- AKHNMLFCWUSKQB-UHFFFAOYSA-L sodium thiosulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=S AKHNMLFCWUSKQB-UHFFFAOYSA-L 0.000 claims description 3
- 235000019345 sodium thiosulphate Nutrition 0.000 claims description 3
- 239000002904 solvent Substances 0.000 claims description 3
- RYHBNJHYFVUHQT-UHFFFAOYSA-N 1,4-Dioxane Chemical compound C1COCCO1 RYHBNJHYFVUHQT-UHFFFAOYSA-N 0.000 claims description 2
- 125000006282 2-chlorobenzyl group Chemical group [H]C1=C([H])C(Cl)=C(C([H])=C1[H])C([H])([H])* 0.000 claims description 2
- 125000000094 2-phenylethyl group Chemical group [H]C1=C([H])C([H])=C(C([H])=C1[H])C([H])([H])C([H])([H])* 0.000 claims description 2
- WKBOTKDWSSQWDR-UHFFFAOYSA-N Bromine atom Chemical compound [Br] WKBOTKDWSSQWDR-UHFFFAOYSA-N 0.000 claims description 2
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 claims description 2
- DWAQJAXMDSEUJJ-UHFFFAOYSA-M Sodium bisulfite Chemical compound [Na+].OS([O-])=O DWAQJAXMDSEUJJ-UHFFFAOYSA-M 0.000 claims description 2
- 125000001797 benzyl group Chemical group [H]C1=C([H])C([H])=C(C([H])=C1[H])C([H])([H])* 0.000 claims description 2
- GDTBXPJZTBHREO-UHFFFAOYSA-N bromine Substances BrBr GDTBXPJZTBHREO-UHFFFAOYSA-N 0.000 claims description 2
- 229910052794 bromium Inorganic materials 0.000 claims description 2
- 229910052801 chlorine Inorganic materials 0.000 claims description 2
- 239000000460 chlorine Substances 0.000 claims description 2
- 125000005982 diphenylmethyl group Chemical group [H]C1=C([H])C([H])=C(C([H])=C1[H])C([H])(*)C1=C([H])C([H])=C([H])C([H])=C1[H] 0.000 claims description 2
- PNDPGZBMCMUPRI-UHFFFAOYSA-N iodine Chemical compound II PNDPGZBMCMUPRI-UHFFFAOYSA-N 0.000 claims description 2
- 239000003960 organic solvent Substances 0.000 claims description 2
- 125000006503 p-nitrobenzyl group Chemical group [H]C1=C([H])C(=C([H])C([H])=C1[N+]([O-])=O)C([H])([H])* 0.000 claims description 2
- RGSFGYAAUTVSQA-UHFFFAOYSA-N pentamethylene Natural products C1CCCC1 RGSFGYAAUTVSQA-UHFFFAOYSA-N 0.000 claims description 2
- 125000006239 protecting group Chemical group 0.000 claims description 2
- 238000010791 quenching Methods 0.000 claims description 2
- 230000000171 quenching effect Effects 0.000 claims description 2
- HRZFUMHJMZEROT-UHFFFAOYSA-L sodium disulfite Chemical compound [Na+].[Na+].[O-]S(=O)S([O-])(=O)=O HRZFUMHJMZEROT-UHFFFAOYSA-L 0.000 claims description 2
- 235000010267 sodium hydrogen sulphite Nutrition 0.000 claims description 2
- 229940001584 sodium metabisulfite Drugs 0.000 claims description 2
- 235000010262 sodium metabisulphite Nutrition 0.000 claims description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 2
- 125000000229 (C1-C4)alkoxy group Chemical group 0.000 abstract description 12
- 125000003903 2-propenyl group Chemical group [H]C([*])([H])C([H])=C([H])[H] 0.000 abstract description 4
- 125000002252 acyl group Chemical group 0.000 abstract description 4
- 125000002485 formyl group Chemical group [H]C(*)=O 0.000 abstract description 4
- 125000001181 organosilyl group Chemical group [SiH3]* 0.000 abstract description 4
- 125000000391 vinyl group Chemical group [H]C([*])=C([H])[H] 0.000 abstract description 4
- 229920002554 vinyl polymer Polymers 0.000 abstract description 4
- 0 *C1=CC(*)=CC(/C=C/C2=CC=C(C)C=C2)=C1.*C1=CC(C)=CC(/C=C\C2=CC=C(C)C=C2)=C1 Chemical compound *C1=CC(*)=CC(/C=C/C2=CC=C(C)C=C2)=C1.*C1=CC(C)=CC(/C=C\C2=CC=C(C)C=C2)=C1 0.000 description 6
- 230000015572 biosynthetic process Effects 0.000 description 5
- DNTQLVRXOUFTAQ-WUKNDPDISA-N 1,3-bis(phenylmethoxy)-5-[(e)-2-(4-phenylmethoxyphenyl)ethenyl]benzene Chemical compound C=1C=CC=CC=1COC(C=C1)=CC=C1\C=C\C(C=C(OCC=1C=CC=CC=1)C=1)=CC=1OCC1=CC=CC=C1 DNTQLVRXOUFTAQ-WUKNDPDISA-N 0.000 description 4
- 238000002360 preparation method Methods 0.000 description 4
- 238000005160 1H NMR spectroscopy Methods 0.000 description 3
- XEKOWRVHYACXOJ-UHFFFAOYSA-N Ethyl acetate Chemical compound CCOC(C)=O XEKOWRVHYACXOJ-UHFFFAOYSA-N 0.000 description 3
- 238000003786 synthesis reaction Methods 0.000 description 3
- ZCYVEMRRCGMTRW-UHFFFAOYSA-N 7553-56-2 Chemical compound [I] ZCYVEMRRCGMTRW-UHFFFAOYSA-N 0.000 description 2
- IAZDPXIOMUYVGZ-WFGJKAKNSA-N Dimethyl sulfoxide Chemical compound [2H]C([2H])([2H])S(=O)C([2H])([2H])[2H] IAZDPXIOMUYVGZ-WFGJKAKNSA-N 0.000 description 2
- RRHGJUQNOFWUDK-UHFFFAOYSA-N Isoprene Chemical compound CC(=C)C=C RRHGJUQNOFWUDK-UHFFFAOYSA-N 0.000 description 2
- JLTDJTHDQAWBAV-UHFFFAOYSA-N N,N-dimethylaniline Chemical compound CN(C)C1=CC=CC=C1 JLTDJTHDQAWBAV-UHFFFAOYSA-N 0.000 description 2
- MZRVEZGGRBJDDB-UHFFFAOYSA-N N-Butyllithium Chemical compound [Li]CCCC MZRVEZGGRBJDDB-UHFFFAOYSA-N 0.000 description 2
- HEDRZPFGACZZDS-MICDWDOJSA-N Trichloro(2H)methane Chemical compound [2H]C(Cl)(Cl)Cl HEDRZPFGACZZDS-MICDWDOJSA-N 0.000 description 2
- VSCWAEJMTAWNJL-UHFFFAOYSA-K aluminium trichloride Chemical compound Cl[Al](Cl)Cl VSCWAEJMTAWNJL-UHFFFAOYSA-K 0.000 description 2
- 230000004071 biological effect Effects 0.000 description 2
- ILAHWRKJUDSMFH-UHFFFAOYSA-N boron tribromide Chemical compound BrB(Br)Br ILAHWRKJUDSMFH-UHFFFAOYSA-N 0.000 description 2
- 239000003153 chemical reaction reagent Substances 0.000 description 2
- 238000004440 column chromatography Methods 0.000 description 2
- 238000002425 crystallisation Methods 0.000 description 2
- 230000008025 crystallization Effects 0.000 description 2
- 231100001261 hazardous Toxicity 0.000 description 2
- 238000004128 high performance liquid chromatography Methods 0.000 description 2
- 229910052740 iodine Inorganic materials 0.000 description 2
- 239000011630 iodine Substances 0.000 description 2
- ZRSNZINYAWTAHE-UHFFFAOYSA-N p-methoxybenzaldehyde Chemical compound COC1=CC=C(C=O)C=C1 ZRSNZINYAWTAHE-UHFFFAOYSA-N 0.000 description 2
- AOJFQRQNPXYVLM-UHFFFAOYSA-N pyridin-1-ium;chloride Chemical compound [Cl-].C1=CC=[NH+]C=C1 AOJFQRQNPXYVLM-UHFFFAOYSA-N 0.000 description 2
- 239000011541 reaction mixture Substances 0.000 description 2
- IGWQNLJWVJDSQG-UHFFFAOYSA-N (3,5-dimethoxyphenyl)methyl-triphenylphosphanium Chemical class COC1=CC(OC)=CC(C[P+](C=2C=CC=CC=2)(C=2C=CC=CC=2)C=2C=CC=CC=2)=C1 IGWQNLJWVJDSQG-UHFFFAOYSA-N 0.000 description 1
- DNTQLVRXOUFTAQ-MSUUIHNZSA-N 1,3-bis(phenylmethoxy)-5-[(z)-2-(4-phenylmethoxyphenyl)ethenyl]benzene Chemical compound C=1C=CC=CC=1COC(C=C1)=CC=C1\C=C/C(C=C(OCC=1C=CC=CC=1)C=1)=CC=1OCC1=CC=CC=C1 DNTQLVRXOUFTAQ-MSUUIHNZSA-N 0.000 description 1
- SIMYWHHAEQQGEH-MAZDBSFSSA-N 5-[(E)-2-(4-hydroxyphenyl)ethenyl]benzene-1,3-diol Chemical compound C1=CC(O)=CC=C1\C=C\C1=CC(O)=CC(O)=C1.C1=CC(O)=CC=C1\C=C\C1=CC(O)=CC(O)=C1 SIMYWHHAEQQGEH-MAZDBSFSSA-N 0.000 description 1
- ABLZXFCXXLZCGV-UHFFFAOYSA-N Phosphorous acid Chemical class OP(O)=O ABLZXFCXXLZCGV-UHFFFAOYSA-N 0.000 description 1
- QNVSXXGDAPORNA-UHFFFAOYSA-N Resveratrol Natural products OC1=CC=CC(C=CC=2C=C(O)C(O)=CC=2)=C1 QNVSXXGDAPORNA-UHFFFAOYSA-N 0.000 description 1
- 239000004133 Sodium thiosulphate Substances 0.000 description 1
- 238000007239 Wittig reaction Methods 0.000 description 1
- 125000002777 acetyl group Chemical group [H]C([H])([H])C(*)=O 0.000 description 1
- 150000001336 alkenes Chemical class 0.000 description 1
- 150000003934 aromatic aldehydes Chemical class 0.000 description 1
- 125000003236 benzoyl group Chemical group [H]C1=C([H])C([H])=C(C([H])=C1[H])C(*)=O 0.000 description 1
- 125000004063 butyryl group Chemical group O=C([*])C([H])([H])C([H])([H])C([H])([H])[H] 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 238000009833 condensation Methods 0.000 description 1
- 230000005494 condensation Effects 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000017858 demethylation Effects 0.000 description 1
- 238000010520 demethylation reaction Methods 0.000 description 1
- 150000002019 disulfides Chemical class 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
- 125000006232 ethoxy propyl group Chemical group [H]C([H])([H])C([H])([H])OC([H])([H])C([H])([H])C([H])([H])* 0.000 description 1
- 125000005448 ethoxyethyl group Chemical group [H]C([H])([H])C([H])([H])OC([H])([H])C([H])([H])* 0.000 description 1
- 125000005745 ethoxymethyl group Chemical group [H]C([H])([H])C([H])([H])OC([H])([H])* 0.000 description 1
- 125000001495 ethyl group Chemical group [H]C([H])([H])C([H])([H])* 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 125000000959 isobutyl group Chemical group [H]C([H])([H])C([H])(C([H])([H])[H])C([H])([H])* 0.000 description 1
- 125000001449 isopropyl group Chemical group [H]C([H])([H])C([H])(*)C([H])([H])[H] 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 125000004184 methoxymethyl group Chemical group [H]C([H])([H])OC([H])([H])* 0.000 description 1
- 125000002496 methyl group Chemical group [H]C([H])([H])* 0.000 description 1
- 125000004108 n-butyl group Chemical group [H]C([H])([H])C([H])([H])C([H])([H])C([H])([H])* 0.000 description 1
- 125000004123 n-propyl group Chemical group [H]C([H])([H])C([H])([H])C([H])([H])* 0.000 description 1
- 239000012044 organic layer Substances 0.000 description 1
- 238000006552 photochemical reaction Methods 0.000 description 1
- 125000001325 propanoyl group Chemical group O=C([*])C([H])([H])C([H])([H])[H] 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 230000002441 reversible effect Effects 0.000 description 1
- 125000002914 sec-butyl group Chemical group [H]C([H])([H])C([H])([H])C([H])(*)C([H])([H])[H] 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- PJANXHGTPQOBST-VAWYXSNFSA-N trans-stilbene Polymers C=1C=CC=CC=1/C=C/C1=CC=CC=C1 PJANXHGTPQOBST-VAWYXSNFSA-N 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C37/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring
- C07C37/01—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring by replacing functional groups bound to a six-membered aromatic ring by hydroxy groups, e.g. by hydrolysis
- C07C37/055—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring by replacing functional groups bound to a six-membered aromatic ring by hydroxy groups, e.g. by hydrolysis the substituted group being bound to oxygen, e.g. ether group
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C41/00—Preparation of ethers; Preparation of compounds having groups, groups or groups
- C07C41/01—Preparation of ethers
- C07C41/32—Preparation of ethers by isomerisation
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07B—GENERAL METHODS OF ORGANIC CHEMISTRY; APPARATUS THEREFOR
- C07B2200/00—Indexing scheme relating to specific properties of organic compounds
- C07B2200/09—Geometrical isomers
Definitions
- the present invention relates to a method of converting (Z)-1-(3,5-disubstituted phenyl)-2-(4-substituted phenyl)ethene of general formula (II) to (E)-1-(3,5-disubstituted phenyl)-2-(4-substituted phenyl)ethene of general formula (I) wherein R 1 , R 2 and R 3 are same or different and independently represent (C 1 -C 4 )alkyl, (C 1 -C 4 )alkoxy(C 1 -C 4 )alkyl, (C 1 -C 4 )alkoxy(C 1 -C 4 )alkoxy(C 1 -C 4 )alkyl, allyl, vinyl, silyl, formyl, acyl, aryl(C 1 -C 4 )alkyl or substituted aryl(C 1 -C 4 )alkyl group.
- the compound of formula (I) is useful as a key intermediate in the preparation of E-resveratrol of the formula (III), without contamination of the corresponding Z-isomer, which is formed during the process of synthesis.
- E-resveratrol has broad-spectrum biological activity.
- the preparation of E-resveratrol can be accomplished quite easily and inexpensively.
- U.S. Pat. No. 6,048,903 describes the synthesis of E-resveratrol by the Wittig reaction of 3,5-dimethoxybenzyltriphenyl phosphonium salt with p-anisaldehyde in the presence of n-butyl lithium.
- the mixture of Z- and E-olefins so obtained is demethylated with large amount of boron tribromide to get very low yield of the product.
- This method suffers from the low quality and use of expensive and hazardous reagents.
- WO 00/21368 describes the condensation of phosphonate esters with aromatic aldehydes followed by demethylation using pyridine hydrochloride. In this method also the yields are low & the process is not commercially attractive.
- the objective of the present invention is to prepare exclusively the (E)-1-(3,5-disubstituted phenyl)-2-(4-substituted phenyl)ethene of general formula (I).
- Another objective of the invention is to develop a simple, eco-friendly commercial method for converting Z-isomer of the formula (II) to the E-isomer of the formula (I).
- Still another objective is to avoid the use of purification techniques like solvent crystallization & column chromatography.
- Yet another objective of the present invention is to provide a simple and effective process without using photochemical reaction in the manufacturing process.
- Still another objective of the present invention is to provide a high-yielding method of producing exclusively the E-resveratrol of the formula (III) from (E)-1-(3,5-disubstituted phenyl)-2-(4-substituted phenyl)ethene of general formula (I).
- the present invention relates to a method of converting (Z)-1-(3,5-disubstituted phenyl)-2-(4-substituted phenyl)ethene of general formula (II) to (E)-1-(3,5-disubstituted phenyl)-2-(4-substituted phenyl)ethene of general formula (I) wherein R 1 , R 2 and R 3 are same or different and independently represent (C 1 -C 4 )alkyl, (C 1 -C 4 )alkoxy(C 1 -C 4 )alkyl, (C 1 -C 4 )alkoxy(C 1 -C 4 )alkoxy(C 1 -C 4 )alkyl, allyl, vinyl, silyl, formyl, acyl, aryl(C 1 -C 4 )alkyl or substituted aryl(C 1 -C 4 )alkyl group,
- the groups represented by R 1 , R 2 , and R 3 are selected from (C 1 -C 4 )alkyl group such as methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl; (C 1 -C 4 )alkoxy(C 1 -C 4 )alkyl group such as methoxymethyl, methoxyethyl, methoxypropyl, ethoxymethyl, ethoxyethyl, ethoxypropyl; (C 1 -C 4 )alkoxy(C 1 -C 4 )alkoxy(C 1 -C 4 )alkyl group such as methoxyethoxymethyl, methoxyethoxyethyl; allyl, vinyl, silyl, formyl, acyl group such as acetyl, propanoyl, butanoyl or benzoyl;
- the solvents used in step (a) are selected from chloroform, dichloromethane, dioxane, THF, methanol, ethanol or isopropanol and the like, preferably dichloromethane.
- the stereochemical conversion is carried out at a temperature in the range of ⁇ 10° C. to +110° C., and particularly, 0-40° C.
- the halogen used in step (a) is selected from iodine, chlorine or bromine, in catalytic quantities ranging from 0.1% w/w to 10% w/w, more particularly, from 1% w/w to 5% w/w.
- the reducing agent used in step (b) is selected from olefins like cyclohexene, cyclopentene, isoprene or inorganic reagents like sodium metabisulfite, sodium thiosulfate, sodium bisulfite and the like.
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
A method of converting (Z)-1-(3,5-disubstituted phenyl)-2-(4-substituted phenyl)ethene of general formula (II) to (E)-1-(3,5-disubstituted phenyl)-2-(4-substituted phenyl)ethene of general formula (I)
wherein R1, R2, and R3 are the same or different and independently represent (C1-C4)alkyl, (C1-C4)alkoxy(C1-C4)alkyl, (C1-C4)alkoxy(C1-C4)alkoxy(C1-C4)alkyl, allyl, vinyl, silyl, formyl, acyl, aryl(C1-C4)alkyl or substituted aryl(C1-C4)alkyl group. The present invention also provides a process for the conversion of (E)-(3,5-disubstituted phenyl-2-(4-substituted phenyl)ethene of general formula (I) to E-resveratrol of formula (III).
wherein R1, R2, and R3 are the same or different and independently represent (C1-C4)alkyl, (C1-C4)alkoxy(C1-C4)alkyl, (C1-C4)alkoxy(C1-C4)alkoxy(C1-C4)alkyl, allyl, vinyl, silyl, formyl, acyl, aryl(C1-C4)alkyl or substituted aryl(C1-C4)alkyl group. The present invention also provides a process for the conversion of (E)-(3,5-disubstituted phenyl-2-(4-substituted phenyl)ethene of general formula (I) to E-resveratrol of formula (III).
Description
The present invention relates to a method of converting (Z)-1-(3,5-disubstituted phenyl)-2-(4-substituted phenyl)ethene of general formula (II) to (E)-1-(3,5-disubstituted phenyl)-2-(4-substituted phenyl)ethene of general formula (I)
wherein R1, R2 and R3 are same or different and independently represent (C1-C4)alkyl, (C1-C4)alkoxy(C1-C4)alkyl, (C1-C4)alkoxy(C1-C4)alkoxy(C1-C4)alkyl, allyl, vinyl, silyl, formyl, acyl, aryl(C1-C4)alkyl or substituted aryl(C1-C4)alkyl group.
wherein R1, R2 and R3 are same or different and independently represent (C1-C4)alkyl, (C1-C4)alkoxy(C1-C4)alkyl, (C1-C4)alkoxy(C1-C4)alkoxy(C1-C4)alkyl, allyl, vinyl, silyl, formyl, acyl, aryl(C1-C4)alkyl or substituted aryl(C1-C4)alkyl group.
The compound of formula (I) is useful as a key intermediate in the preparation of E-resveratrol of the formula (III), without contamination of the corresponding Z-isomer, which is formed during the process of synthesis. E-resveratrol has broad-spectrum biological activity. Moreover, the preparation of E-resveratrol can be accomplished quite easily and inexpensively.
In view of the vital biological activities of the polyhydroxylated trans-stilbenes, here have been a few methods reported for the synthesis of these compounds.
U.S. Pat. No. 6,048,903 describes the synthesis of E-resveratrol by the Wittig reaction of 3,5-dimethoxybenzyltriphenyl phosphonium salt with p-anisaldehyde in the presence of n-butyl lithium. In this method the mixture of Z- and E-olefins so obtained is demethylated with large amount of boron tribromide to get very low yield of the product. This method suffers from the low quality and use of expensive and hazardous reagents.
WO 00/21368 describes the condensation of phosphonate esters with aromatic aldehydes followed by demethylation using pyridine hydrochloride. In this method also the yields are low & the process is not commercially attractive.
Drewes, S. E.; Fletcher, I. P J. Chem. Soc. Perkin Trans. 1 1974, 961-962 & Bajaj, R.; Gill, M. T.; McLaughiln, J. L. Rev. Latinoamer Quim. 1987, 18, 79-80 reported the synthesis of analogs of E-resveratrol wherein a mixture of E- & Z-isomer is obtained.
Cunningham, J.; Haslam, E.; Haworth, R. D. J. Chem. Soc. 1963, 2875-2883 disclosed a different route, which comprises reaction of 3,5-dihydroxyphenylacetate and 3,4-dihydroxybenzaldehyde in acetic anhydride, decarboxylation of the ensuing 3,3′,4,5′-tetraacetoxystilbene-α-carboxylic acid with copper and quinoline at high temperature, and hydrolysis of the resulting piceatannol tetraacetate with sodium hydroxide. The reported yields in these methods are moderate to low.
Ali, M. A.; Kondo, K.; Tsuda, Y. Chem. Pharm. Bull. 1992, 40(5) 1130-1136 described the Wittig reaction, wherein the undesired Z-isomers are reported to form to the extent of 52% along with the desired E-isomers (48%) when potassium tert-butoxide is employed.
Cushman, M.; Nagarathnam, D.; Gopal, D. et al. J. Med. Chem. 1992, 35 (12), 2293-2306; Chen, Yi-Ping; Lei, Tong-Kang. Zhongguo Yiyao Gongye Zazhi 2000, 31(7), 334-336 disclosed the formation of Z-isomers to the extent of 45% (E: 55%) when sodium hydride is used.
All of the above prior art disclosures have following limitations because of which the process is commercially not suitable and hazardous:
A mixture of Z- and E-isomers is always encountered and the isomers are separated by column chromatography or by crystallization techniques. Conversion of Z- into E-isomers with the aid of photochemical techniques are reported, wherein the mixture of Z- and E-isomers are irradiated with high powered lamps in the presence of catalysts like diaryl disulfides at high temperature.
In addition, the disulfides, which are essential for photochemical conversions, produce very bad smell and not environmentally acceptable.
Thus these techniques make the process not preferable for the industrial scale and, more over, these are non eco-friendly.
The objective of the present invention is to prepare exclusively the (E)-1-(3,5-disubstituted phenyl)-2-(4-substituted phenyl)ethene of general formula (I).
Another objective of the invention is to develop a simple, eco-friendly commercial method for converting Z-isomer of the formula (II) to the E-isomer of the formula (I).
Still another objective is to avoid the use of purification techniques like solvent crystallization & column chromatography.
Yet another objective of the present invention is to provide a simple and effective process without using photochemical reaction in the manufacturing process.
Still another objective of the present invention is to provide a high-yielding method of producing exclusively the E-resveratrol of the formula (III) from (E)-1-(3,5-disubstituted phenyl)-2-(4-substituted phenyl)ethene of general formula (I).
Accordingly, the present invention relates to a method of converting (Z)-1-(3,5-disubstituted phenyl)-2-(4-substituted phenyl)ethene of general formula (II) to (E)-1-(3,5-disubstituted phenyl)-2-(4-substituted phenyl)ethene of general formula (I)
wherein R1, R2 and R3 are same or different and independently represent (C1-C4)alkyl, (C1-C4)alkoxy(C1-C4)alkyl, (C1-C4)alkoxy(C1-C4)alkoxy(C1-C4)alkyl, allyl, vinyl, silyl, formyl, acyl, aryl(C1-C4)alkyl or substituted aryl(C1-C4)alkyl group, the said process comprising the steps of:
wherein R1, R2 and R3 are same or different and independently represent (C1-C4)alkyl, (C1-C4)alkoxy(C1-C4)alkyl, (C1-C4)alkoxy(C1-C4)alkoxy(C1-C4)alkyl, allyl, vinyl, silyl, formyl, acyl, aryl(C1-C4)alkyl or substituted aryl(C1-C4)alkyl group, the said process comprising the steps of:
-
- (a) treating an isomeric mixture of (Z)-1-(3,5-disubstituted phenyl)-2(4-substituted phenyl)ethene of the general formula (II) and (E)-1-(3,5-disubstituted phenyl)-2-(4-substituted phenyl)ethene of the general formula (I) or (Z)-1-(3,5-disubstituted phenyl)-2-(4-substituted phenyl)ethene of the general formula (II) with halogen in catalytic amounts, in an organic solvent for a period of 15 min to 16 hrs, at a temperature varying from −10° C. to +110° C.,
- (b) quenching the resulting solution of step (a) into cold water and reducing the halogen using a reducing agent and (c) isolating the product formed in step (b) to produce (E)-1-(3,5-disubstituted phenyl)-2-(4-substituted phenyl)ethene of general formula (I).
In yet another embodiment of the present invention, there is provided a process for the conversion of (E)-1-(3,5-disubstituted phenyl)-2-(4-substituted phenyl)ethene of general formula (I) prepared by a process described above to E-resveratrol of the formula (III) which comprises deprotecting the protecting groups R1, R2, and R3 by conventional methods.
In an embodiment of the present invention, the groups represented by R1, R2, and R3 are selected from (C1-C4)alkyl group such as methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl; (C1-C4)alkoxy(C1-C4)alkyl group such as methoxymethyl, methoxyethyl, methoxypropyl, ethoxymethyl, ethoxyethyl, ethoxypropyl; (C1-C4)alkoxy(C1-C4)alkoxy(C1-C4)alkyl group such as methoxyethoxymethyl, methoxyethoxyethyl; allyl, vinyl, silyl, formyl, acyl group such as acetyl, propanoyl, butanoyl or benzoyl; aryl(C1-C4)alkyl or substituted aryl(C1-C4)alkyl group such as benzyl, phenethyl, diphenylmethyl, p-methoxybenzyl, p-nitrobenzyl, p-methylbenzyl or o-chlorobenzyl.
In yet another embodiment of the present invention, the solvents used in step (a) are selected from chloroform, dichloromethane, dioxane, THF, methanol, ethanol or isopropanol and the like, preferably dichloromethane.
In another embodiment of the present invention, the stereochemical conversion is carried out at a temperature in the range of −10° C. to +110° C., and particularly, 0-40° C.
In still another embodiment of the present invention, the halogen used in step (a) is selected from iodine, chlorine or bromine, in catalytic quantities ranging from 0.1% w/w to 10% w/w, more particularly, from 1% w/w to 5% w/w.
In still another embodiment of the present invention, the reducing agent used in step (b) is selected from olefins like cyclohexene, cyclopentene, isoprene or inorganic reagents like sodium metabisulfite, sodium thiosulfate, sodium bisulfite and the like.
The foregoing technique has been found to be markedly attractive, both from commercial point of view, as well as from a stereo selectivity standpoint, and affords an almost exclusive formation of the E-isomer and is also free from the limitations discussed above.
The starting materials of the present invention, (Z) 1-(3,5-disubstituted phenyl)-2-(4-substituted phenyl)ethene of general formula (II) or its mixture with the corresponding E-isomer can be produced by the methods known in the art.
The probable mechanism of the stereochemical conversion is predicted in which a reversible addition-elimination of iodine to the double bond of the subject compound of the formula (II), which results in the formation of stable E-isomer exclusively has been suggested. The mechanism is shown in Scheme-1 below:
The present invention is illustrated with the following examples, which should not be construed to limit the scope of the invention.
Preparation of (E)-1-(4-(benzyloxy)phenyl)-2-(3,5-bis(benzyloxy)phenyl)ethene (I)
A mixture of Z- and E-isomers, (Z)-1-(4-(benzyloxy)phenyl)-2-(3,5-bis(benzyloxy)phenyl)ethene and (E)-1-(4-(benzyloxy)phenyl)-2-(3,5-bis(benzyloxy)phenyl)ethene (25 gm) in an approximate ratio of 45%:55%, respectively, was dissolved in chloroform (200 ml). To the clear solution, iodine (1 gm) was added at 28-33° C. and maintained at this temperature for 12 hours. After the reaction was over, the reaction mixture was quenched with sodium thiosulphate, extracted into chloroform and the organic layer concentrated under vacuum. Treatment of the resulting residue, with methanol followed by filtration afforded (E-1-(4-(benzyloxy)phenyl)-2-(3,5-bis(benzyloxy)phenyl)ethene in quantitative yield and in exclusive E-form. M. pt. 156-158° C.; 1H NMR (CDCl3, Bruker 400 MHz Avance): δ 5.09 (2, 4H), 5.11 (s, 2H), 6.56 (t, J=2.1 Hz), 6.77 (d, J=2.1 Hz, 2H), 6.91 (d, J=16.2 Hz, 1H), 6.99 (d, J=8.7 Hz, 2H), 7.04 (d, J=16.2 HZ, 1H), 7.34-7.48 (m, 17H); Mass m/e: 498.2. HPLC confirms that the Z-isomer content is <0.01%. (For HPLC analysis, the Z-isomer was produced and the stereochemistry confirmed by 1H NMR).
Preparation of (E)1-(3,5-dihydroxyphenyl)-2-(4-hydroxyphenyl)ethene of the formula (III):
Into a 3 lit. round-bottomed flask equipped with a thermometer were added aluminum chloride (390.35 gm) and N,N-dimethylaniline (413.10 gm) maintaining the temperature at 40-50° C. To this solution, a solution of (E)-1-(4-(benzyloxy)phenyl)-2-(3,5-bis(benzyloxy)phenyl)ethene (243 gm) prepared according to example 1 in dichloromethane was added and stirred well. After the reaction was over, the reaction mixture was acidified, extracted into ethyl acetate and concentrated to get pure (E)1-(3,5-dihydroxyphenyl)-2-(4-hydroxyphenyl)ethene (E-Resveratrol) in the exclusive E- form in 90% yield. 1H NMR (DMSO-d6, Bruker 400 MHz Avarice): δ 6.11 (t, J=1.8 Hz), 6.38 (d, J=1.8 Hz, 2H), 6.75 (d, J=8.5 Hz, 2H), 6.82 (d, J=16.3 Hz, 1H), 6.92 (d, J=16.3 Hz), 7.39 (d, J=8.4 Hz, 2H); Mass m/e: 228.2.
Claims (7)
1. A method of converting (Z)-1-(3,5-disubstituted phenyl)-2-(4-substituted phenyl)ethene of general formula (II) to (E)-1-(3,5-disubstituted phenyl)-2-(4-substituted phenyl)ethene of general formula (I)
wherein R1, R2, and R3 are the same or different and independently represent aryl(C1-C4) alkyl group or substituted aryl(C1-C4)alkyl group, the method comprising the steps of:
(a) treating an isomeric mixture of (Z)-1-(3,5-disubstituted phenyl)-2-(4-substituted phenyl)ethene of the general formula (II) and (E)-1-(3,5-disubstituted phenyl)-2-(4-substituted phenyl)ethene of the general formula (I) or (Z)-1-(3,5-disubstituted phenyl)-2-(4-substituted phenyl)ethene of the general formula (II)
with a halogen in catalytic amounts, in an organic solvent for a period of 15 min to 16 hrs, at a temperature ranging from −10° C. to +110° C.;
(b) quenching the resulting solution of step (a) in water and reducing the halogen using a reducing agent; and
(c) isolating the product formed in step (b) to produce (E)1-(3,5-disubstituted phenyl)-2-(4-substituted phenyl)ethene of general formula (I).
2. The method according to claim 1 , wherein the groups represented by R1, R2, and R3 are benzyl, phenethyl, diphenylmethyl, p-methoxybenzyl, p-nitrobenzyl, p-methylbenzyl, or o-chlorobenzyl.
3. The method according to claim 1 , wherein the solvent used in step (a) is selected from the group consisting of chloroform, dichloromethane, dioxane, THF, methanol, ethanol, and isopropanol.
4. The method according to claim 1 , wherein the stereochemical conversion is carried out at a temperature in the range of 0-40° C.
5. The method according to claim 1 , wherein the halogen in step (a) is iodine, chlorine, or bromine, in catalytic quantities ranging from 0.1% w/w to 10% w/w.
6. The method according to claim 1 , wherein the reducing agent used in step (b) is selected from the group consisting of cyclohexene, cyclopentene, sodium metabisulfite, sodium thiosulfate, and sodium bisulfite.
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Publication number | Priority date | Publication date | Assignee | Title |
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DE112007000790T5 (en) | 2006-03-28 | 2009-04-23 | Council Of Scientific & Industrial Research | Single stage microwave-induced process for the preparation of substituted stilbenes and their analogues |
US20100324342A1 (en) * | 2007-10-03 | 2010-12-23 | Clariant Specialty Fine Chemicals (France) | Process for the synthesis of polyhydroxystilbene compounds |
US8716532B2 (en) | 2009-03-27 | 2014-05-06 | Council Of Scientific And Industrial Research | One pot multicomponent synthesis of some novel hydroxy stilbene derivatives with alpha, beta-carbonyl conjugation under microwave irradiation |
US10207988B2 (en) | 2011-06-27 | 2019-02-19 | The Jackson Laboratory | Methods and compositions for treatment of cancer and autoimmune disease |
US10927075B2 (en) | 2014-12-12 | 2021-02-23 | The Jackson Laboratory | Compositions and methods relating to the treatment of cancer, autoimmune disease, and neurodegenerative disease |
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Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2311093A (en) * | 1939-01-13 | 1943-02-16 | Schering Corp | Rearrangement of iso-dialkylstilbestrols to dialkylstilbestrols |
US2346049A (en) * | 1941-02-13 | 1944-04-04 | Lilly Co Eli | Method of producing dialkoxy stilbenes |
US6048903A (en) * | 1994-05-03 | 2000-04-11 | Robert Toppo | Treatment for blood cholesterol with trans-resveratrol |
WO2001060774A1 (en) * | 2000-02-16 | 2001-08-23 | Brigham Young University | Synthesis of resveratrol |
-
2002
- 2002-08-07 WO PCT/IB2002/003225 patent/WO2004009539A2/en not_active Application Discontinuation
- 2002-12-05 US US10/310,048 patent/US6844471B2/en not_active Expired - Fee Related
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2311093A (en) * | 1939-01-13 | 1943-02-16 | Schering Corp | Rearrangement of iso-dialkylstilbestrols to dialkylstilbestrols |
US2346049A (en) * | 1941-02-13 | 1944-04-04 | Lilly Co Eli | Method of producing dialkoxy stilbenes |
US6048903A (en) * | 1994-05-03 | 2000-04-11 | Robert Toppo | Treatment for blood cholesterol with trans-resveratrol |
WO2001060774A1 (en) * | 2000-02-16 | 2001-08-23 | Brigham Young University | Synthesis of resveratrol |
Non-Patent Citations (1)
Title |
---|
Kim, J. Med.Chem., vol. 45, pp. 160-164 (Published on Web Dec. 7, 2001). * |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
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DE112007000790T5 (en) | 2006-03-28 | 2009-04-23 | Council Of Scientific & Industrial Research | Single stage microwave-induced process for the preparation of substituted stilbenes and their analogues |
US20100324342A1 (en) * | 2007-10-03 | 2010-12-23 | Clariant Specialty Fine Chemicals (France) | Process for the synthesis of polyhydroxystilbene compounds |
US8399714B2 (en) | 2007-10-03 | 2013-03-19 | Clariant Speciality Fine Chemicals (France) | Process for the synthesis of polyhydroxystilbene compounds |
US8716532B2 (en) | 2009-03-27 | 2014-05-06 | Council Of Scientific And Industrial Research | One pot multicomponent synthesis of some novel hydroxy stilbene derivatives with alpha, beta-carbonyl conjugation under microwave irradiation |
US10207988B2 (en) | 2011-06-27 | 2019-02-19 | The Jackson Laboratory | Methods and compositions for treatment of cancer and autoimmune disease |
US10927075B2 (en) | 2014-12-12 | 2021-02-23 | The Jackson Laboratory | Compositions and methods relating to the treatment of cancer, autoimmune disease, and neurodegenerative disease |
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WO2004009539A3 (en) | 2005-05-26 |
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